They found that only 9% (376) of adverse drug reactions were said to have been reported to the
CSM.

However, 53% (27) of the events classified as serious adverse drug reactions were reported.

The researchers acknowledge that reporting of serious suspected adverse reactions has improved since a previous study done in 1998.

Researcher Dr Saad Shakir said: "Our results suggest that family doctors are five times more likely to report serious events on black-triangle drugs than non-serious labelled events.

"This finding raises the question of whether doctors are fully aware of the meaning of the black triangle, whereby all suspected adverse drug reactions should be reported to the CSM."

No time

Dr Chaand Nagpaul, a GP in Stanmore, Middlesex, and a member of the British Medical Association's prescribing sub-committee, told BBC News Online that doctors simply did not have enough time to complete every administrative task asked of them.

However, he was confident that serious side effects were being properly reported.

Dr Nagpaul said: "GPs are being asked to do the impossible in the eight minutes they spend with each patient.

"In a short, hurried consultation there is not going to be enough time for patients to discuss all side effects, and for GPs to check the product data sheet to ascertain whether it is a side effect and fill in the necessary administration forms to report it.

"A lot of short cuts take place in a consultation because GPs have such limited time. They must concentrate on treating the patient, and inevitably administrative tasks fall behind."

Dr Nagpaul said extra resources were needed to give GPs more time for patients. He also said patients should be given forms to report side effects directly to the CSM.